http://needhamag.com/innovative_product_sales/stream_bars_for_uniform_liquid_fertilizer_application.php

Here's a discussion on the various options, strengths and weaknesses.  $45 is way too high for stream bars.  I haven't priced them lately, but would think you could get the streamer, disc orifice and adapter for the stream bar for about $15 give or take.  Stream bars do require a preorifice and the disks work great and are much cheaper than the Chafer caps which are prone to leak if not run in a narrow pressure range.

The problem with 3 hole caps is that they are height sensitive as is discussed in the link above.  The only cap that I have found that is relatively not height sensitive is the Hardi Quintastream which operates on an overlap of 110 degrees with the effect somewhat like a 110 flat fan only streamed and not sprayed.

As far as the PVC idea -- pretty creative -- but I would have one concern.  The Chafer streamers are actually a flow divider so that the stream from the preorifice is equally divided into 4 streams.  I would question whether the drilled holes in PVC would accurately metered like a true flow divider.  Not saying that it's not possible -- just that it's a question I would want answered. 

One other thing -- I don't think Chafer is the only company making stream bars.  It seems that there is another manufacturer whose stream bars costs a couple of bucks less as posted in a previous thread.